Salut,
Rien de mieux qu'un exemple...
Regarde:
Tu l'a voit l'erreur ?
C'est tout ça:
Lorsqu'y a pas d'erreur, c'est en ligne, tout "beau" dès qu'y a une erreur, ça va devenir moche 
Après, il y des erreurs d'une ligne... Donc ça vaut parfois la peine de lire (et oui, c'est pas si compliqué) tout tes logs.
Cordialement,
Detobel36
Rien de mieux qu'un exemple...
Regarde:
Code:
2013-03-01 20:17:56 [INFO] Starting minecraft server version 1.4.7
2013-03-01 20:17:56 [INFO] Loading properties
2013-03-01 20:17:56 [INFO] Default game type: SURVIVAL
2013-03-01 20:17:56 [INFO] Generating keypair
2013-03-01 20:17:57 [INFO] Starting Minecraft server on *:25565
2013-03-01 20:17:58 [INFO] This server is running CraftBukkit version git-Bukkit-1.4.7-R1.0-b2624jnks (MC: 1.4.7) (Implementing API version 1.4.7-R1.0)
2013-03-01 20:17:58 [SEVERE] Could not load 'plugins\PluginsBaker.jar' in folder 'plugins'
org.bukkit.plugin.UnknownDependencyException: Vault
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:195)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.loadPlugins(CraftServer.java:239)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.<init>(CraftServer.java:217)
at net.minecraft.server.v1_4_R1.PlayerList.<init>(PlayerList.java:55)
at net.minecraft.server.v1_4_R1.DedicatedPlayerList.<init>(SourceFile:11)
at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.java:104)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:399)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
2013-03-01 20:17:58 [SEVERE] Could not load 'plugins\iProfessions.jar' in folder 'plugins'
org.bukkit.plugin.UnknownDependencyException: PluginsBaker
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:195)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.loadPlugins(CraftServer.java:239)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.<init>(CraftServer.java:217)
at net.minecraft.server.v1_4_R1.PlayerList.<init>(PlayerList.java:55)
at net.minecraft.server.v1_4_R1.DedicatedPlayerList.<init>(SourceFile:11)
at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.java:104)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:399)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
2013-03-01 20:17:58 [INFO] Preparing level "world"
2013-03-01 20:17:59 [INFO] Preparing start region for level 0 (Seed: 4732451193154106146)
2013-03-01 20:18:00 [INFO] Preparing spawn area: 8%
2013-03-01 20:18:08 [INFO] Preparing spawn area: 8%
2013-03-01 20:18:09 [INFO] Preparing spawn area: 32%
2013-03-01 20:18:10 [INFO] Preparing spawn area: 97%
2013-03-01 20:18:10 [INFO] Preparing start region for level 1 (Seed: 4732451193154106146)
2013-03-01 20:18:11 [INFO] Preparing spawn area: 77%
2013-03-01 20:18:11 [INFO] Preparing start region for level 2 (Seed: 4732451193154106146)
2013-03-01 20:18:12 [INFO] Preparing spawn area: 36%
2013-03-01 20:18:13 [INFO] Server permissions file permissions.yml is empty, ignoring it
2013-03-01 20:18:13 [INFO] Done (14,626s)! For help, type "help" or "?"
C'est tout ça:
Code:
[SEVERE] Could not load 'plugins\PluginsBaker.jar' in folder 'plugins'
org.bukkit.plugin.UnknownDependencyException: Vault
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:195)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.loadPlugins(CraftServer.java:239)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.<init>(CraftServer.java:217)
at net.minecraft.server.v1_4_R1.PlayerList.<init>(PlayerList.java:55)
at net.minecraft.server.v1_4_R1.DedicatedPlayerList.<init>(SourceFile:11)
at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.java:104)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:399)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
2013-03-01 20:17:58 [SEVERE] Could not load 'plugins\iProfessions.jar' in folder 'plugins'
org.bukkit.plugin.UnknownDependencyException: PluginsBaker
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:195)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.loadPlugins(CraftServer.java:239)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.<init>(CraftServer.java:217)
at net.minecraft.server.v1_4_R1.PlayerList.<init>(PlayerList.java:55)
at net.minecraft.server.v1_4_R1.DedicatedPlayerList.<init>(SourceFile:11)
at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.java:104)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:399)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)

Après, il y des erreurs d'une ligne... Donc ça vaut parfois la peine de lire (et oui, c'est pas si compliqué) tout tes logs.
Cordialement,
Detobel36
Mais comment je sais où sont les erreurs dans le log ? c'est lorsque c'est marqué [warning] ?